Service sucks

My husband went for his upgrade on 1October2019 at Vodacom Canal Walk. We were given a choice of 2 device packages with different price ranges. He chose the lower price but within half an hour of concluding, he went back to request the more expensive device plan. Long & short of the matter, he was denied, he requested the manager to call him as he needed to understand why he is not allowed to change his mind as a consumer. Heard nothing from the manager, he called back 2 days later to be advised that he needs to escalate it to Head Office and will revert back on a reply. Again no call back from the manager. Today is Saturday and he has not had 1 call back from them. It has taken us to call back several times, leave msgs, have a promise of a call back or e-mail. He was referred to the CRM and even she promised to call back or e-mail yesterday to no avail. I have called the manager of Canal twice since this morning and yet again no response. As a long standing client of Vodacom since the 90's this is pathetic service. Do you think because you have more than enough clients that one does not matter??? That we do not warrant a courtesy of a call back or response??? A very sad pathetic state of service.